All passports seems to be the same size and format, which is interesting because they’re issued by different countries.
Turns out there’s an international board that standardizes things like this: the International Civil Aviation Organization. This is a special agency of the United Nations, based in Montreal, Canada.
There are 192 member countries – almost all the members of the United Nations that have an international airport. It’s governed that the ICAO Council, which is the 36 members of “chief importance” to international air travel.
This organizations maintains all standards around international aviation. Things like:
- Airport codes
- Airline codes
- Aircraft registrations
- and yes, passport sizes
If you’re interested, here’s the passport standard (PDF). It’s Document 9303, entitled “Machine Readable Travel Documents” (MRDT is the technical term for what we call a “passport”). It contains the standards for physical size, and for the picture page with the scannable information (see page 4).